A touch panel usually employs two metal mesh layers correspondingly as an upper touch sensor and a lower touch sensor to sense a touch position on the touch panel. The metal mesh layer includes a number of first metal wires extending in a first direction and a number of second metal wires extending in a second direction. The first metal wires cross with the second metal wires to form a number of meshes. However, the first metal wires of the upper metal mesh layer are usually parallel to the first metal wires of the lower metal mesh layer. Light passing through the upper metal mesh layer and the lower metal mesh layer generates an interference moire, which adversely affects a display performance of a touch display device with the touch panel.